The black-footed cat (Felis nigripes) is endemic to the south-west arid zone of the southern African subregion. Since 1975, black-footed cats are kept at the Zoological Garden of Wuppertal. A retrospective study of necropsy records stated kidney failure as the main mortality cause of captive animals. Further analysis led to the diagnosis of generalized reactive AA amyloidosis in most of the cases. Evaluations of diagnostic tools for the detection of amyloid deposits in vivo as well as measurement of acute-phase protein (APP) levels were performed. APP serum amyloid A (SAA) is the precursor protein in AA amyloidosis. Highly elevated plasma levels of SAA over a prolonged period of time lead to the accumulation of AA filaments in tissues. Moreover the eva-luation of APPs can provide valuable information in the detection of infection, inflammation or trauma, in this case potential primary causes for reactive AA amyloidosis. Concentrations of the APPs SAA, alpha-1 -acid glycoprotein (AGP) and haptoglobin (Hp) were determined. Field research was conducted in order to determine whether AA amyloidosis exists as disorder in free-ranging black-footed cats, as well. Deposits of amyloid were found in biopsies of subcutaneous fat in captive as well as in free-ranging black-footed cats. Concentrations of APPs measured showed correspondence to the major and moderate APPs in domestic cats. No raised levels of either of these proteins were detected in cats with signs of renal insufficiency/amyloidosis, leading to the hypothesis that infections or inflammations are not the primary causes for the disease in this species. Deposits of amyloid A protein were detected in organs of a small number of free-ranging black-footed cats. These findings lead to the conclusion that AA amyloidosis in this species is not a mere problem of captive animals.